B-80 Front PTO/Mower Deck

[Brother Grilka 0]

Hi, I am wondering which of the two pulleys should I have a regular mower deck belt connected to. When I engage the mower deck it strains the engine such that it labors and slows down.

 

Thanks, Duncan

[953 nut 55,262]

Your deck belt should be on the larger pulley on the PTO. 

6 minutes ago, Brother Grilka said:

When I engage the mower deck it strains the engine such that it labors and slows down.

What size deck are you using? Is this happening with your engine at wide open throttle and the deck clear of any tall grass? The deck will load the engine a little but shouldn't labor at WOT. You may want to remove the deck and check the spindles to see if they all turn freely.

[Racinbob 11,082]

It should be on the inside pulley. It shouldn't strain the engine though. Is the deck turning freely?

[oliver2-44 9,756]

Also are the front mule drive pulleys turning freely?

While your checking your deck, also check that the tensioner bar is sliding freely. It has hard plastic bushings it slides on the need to be replaced when they are worn. 

[Brother Grilka 0]

Hi everyone, thanks for the info. Let me clarify my original question. When I engage the deck in neutral it seems to be fine but when I put it in gear and try to move forward the engine labors a lot and everything slows down.

 

I now have the belt on the inner pulley. The Mule Drive is one I just acquired. The v pulley doesn't turn totally freely but I'm not sure if it's enough to be a problem.

Edited August 23, 2023 by Brother Grilka

[Gasaholic 224]

18 minutes ago, Brother Grilka said:

 When I engage the deck in neutral it seems to be fine but when I put it in gear and try to move forward the engine labors a lot and everything slows down.

 

 

Stuck parking brake? Frozen Drive belt idler? 

[Ed Kennell 38,182]

Jack up the rear and rotate each wheel.  Check for noise or tightness.    Check axle bearings for L/R or Up/D axle movement.

 

Does the engine  bog down if the PTO is not engaged?             Is the deck locked into the attach-a-matic properly with the "fork" on the correct rod?

Edited August 23, 2023 by Ed Kennell

[WHX?? 48,821]

Any signs of any belts burning? 

[peter lena 8,631]

@Brother Grilka  collective drag is the killer on  w/h pto/ belt driven anything , with the deck hooked up , belt drive attatched , how easily  /  or resistant does it turn by hand on the drive belt ?  chences are the related  belt driven pulleys , have  bearing lubrication issues , rarely  lubricated / wrong grease , that entire set up should  belt spin easily , every functional area , must be free and smooth ,  you might try that in lowest speed, but think the entire drag set up , will subject your engine /  pto drive a lot of  wear ,  verify what moves easily . probably very little , pete

[Brother Grilka 0]

4 hours ago, peter lena said:

@Brother Grilka  collective drag is the killer on  w/h pto/ belt driven anything , with the deck hooked up , belt drive attatched , how easily  /  or resistant does it turn by hand on the drive belt ?  chences are the related  belt driven pulleys , have  bearing lubrication issues , rarely  lubricated / wrong grease , that entire set up should  belt spin easily , every functional area , must be free and smooth ,  you might try that in lowest speed, but think the entire drag set up , will subject your engine /  pto drive a lot of  wear ,  verify what moves easily . probably very little , pete

 

I suspect peter lena has the right idea here. Is there anything I can do to loosen up the deck spindles and mule drive? The spindles are the self-contained non-greasable kind I think.

[peter lena 8,631]

@Brother Grilka  you just don,t loosen them up , original lubricant , was not a stress rated grease , thaths why  they  fail under a load , its also common to have the same bearings , in both the muel drive , and the mower belt spindles . the pro clutch drive itself , has an inner needle bearing  that needs a hi temp , anti sling grease , the outer sealed bearing to that is also made for heavy side loading .  the non greaseable bearings , are easily , opened up cleaned  out , and repacked with  hi temp , polyurea grease , that will not fail . their is a complete , bearing lubrication upgrade ,for every rotational  part . when converted , the difference is amaizing , no wyining noise , and spins by hand . you might make small improvements , but the entire set up , needs  a re/do , pete